HP-65 & HP-67

[DaveBr]

Thanks to the new programs (thanks Dave Britten) and related posts for both the HP-65 and HP-67, I have been using my 65 and 67 quite a bit in the last week. Both calculators are amazing but entering and debugging programs are WAY easier on the HP-67. Program line numbers, BST and GTO.nnn are incredible improvements. What a difference in only two years!

Dave

P.S.
I just noticed that my HP21 and HP-22 are in TI cases. Is that blasphemy?

[Dave Britten]

I just got another pack of 40 blank program cards in the mail for my 65 (~120 ought to be enough, right???), so I hope to write many more useful and/or interesting programs for it. I may need a few more of these 40-card wallets, though.

I've got one to post that calculates any of the five variables for an IV infusion with linear ramp up/down periods. It's essentially an area-of-a-trapezoid problem with an equation relating total hours, ramp-up hours, ramp-down hours, plateau rate, and total volume. You can enter any 4 variables and solve for the 5th.

I think I also still need to post the markup/margin calculator I did... It relates price, cost, and markup/margin percent. You can enter any two and solve for the third, and also toggle between %-of-cost or %-of-price calculation modes.

I'm really impressed with how much can be done with just 100 partially-merged steps, and 5 subroutine labels! It's wild to think how this little handheld calculator jump started the "I don't have to wait 24 hours to get results back from the computing center" revolution.

[David Hayden]

(01-17-2020 06:17 PM)Dave Britten Wrote:  I'm really impressed with how much can be done with just 100 partially-merged steps, and 5 subroutine labels! It's wild to think how this little handheld calculator jump started the "I don't have to wait 24 hours to get results back from the computing center" revolution.

I recently came across this in the HP-25 Applications Programs. It's from the description of the "sight reduction table" program on page 70:

Quote:This program calculates the computed altitude Hc and azimuth Zn of a celestial body given the observer's latitude L and the local hour angle LHA and declination d of the body. It thus becomes a replacement for the nine volumes of HO 214.

(emphasis added)

A little digging shows that H.O. 214 is "Tables of Computed Altitude and Azimuth" published in 1940.

Just imagine being a navigator with a bookshelf full of these volumes and discovering that for $195 you could get a hand-held machine that could replace them! It must have been truly revolutionary.